The present invention relates generally to portable phones with a hinged lid or cover, and is particularly concerned with a cam retainer for a snap hinge mechanism which snaps the cover into the open and closed positions.
In our co-pending application No. 09/045,153 filed Mar. 19,1998 and entitled xe2x80x9cSnap Hinge Mechanism for Flip Style Portable Phonexe2x80x9d, the contents of which are incorporated herein by reference, a snap hinge mechanism is described in which a hinge pin is biased by a spring into the open and closed positions. The spring acts on a pair of spaced cam portions on the hinge pin so that rotation of the flip or cover in either direction first compresses the spring, and then releases the spring so that the cover is snapped into the open or closed position.
Due to the axial loading and bending forces on the hinge or cam pin, the cam may bend or bow. Such bending may reduce the axial dimension sufficiently to allow the flip cover to disengage from the cam and phone. The user must then re-assemble the parts, which can be difficult and inconvenient.
It is an object of the present invention to provide a new and improved snap hinge mechanism for flip style portable phones with a retainer which reduces the risk of bending or bowing of the hinge pin.
According to the present invention, a portable phone is provided which comprises a phone housing having a keypad on one face, a first end and a second end, a cover hinged to the second end of the housing for movement between a closed position covering at least part of the keypad and an open position, and a hinge mechanism pivotally connecting the cover to the second end of the housing, the hinge mechanism comprising a hinge pin rotatably mounted in the second end of the housing and releasably secured to the cover, and a cam retainer secured in the second end of the housing adjacent the hinge pin and having a portion adjacent a central part of the pin for resisting bending of the pin and disengagement from the cover.
Preferably, the hinge pin is rotatably mounted in a cavity at the second end of the housing and has opposite end portions releasably engaged in corresponding recesses in the cover, and the cam retainer is also mounted in the cavity to extend over one side of the pin. In a preferred embodiment of the invention, a spring member is also mounted in the cavity and bears against the hinge pin so as to urge the cover into the open position as the cover is rotated towards the open position, and into the closed position as the cover is rotated towards the closed position. Preferably, the hinge pin has enlarged cam portions on opposite sides of a central portion of the pin, and the cam portions have opposing flat faces against which the spring acts in the open and closed positions, respectively, so as to releasably hold the hinge pin in the respective positions unless the flip or cover is positively urged away from the position.
As the cover is rotated, simultaneously rotating the pin about the hinge axis, cam surfaces between the flat faces will first compress the spring to increase the biasing force on the hinge pin, and then release the spring after the hinge pin has been rotated through a predetermined angle, snapping the cover into the open or closed position. The cam retainer has recessed areas for extending over the cam portions so that the cam portions can rotate freely back and forth as the cover is opened and closed, and a projecting portion between the recessed areas for extending into close proximity with the central portion of the hinge pin, in order to resist bowing of the pin in this region.
The cam retainer thus prevents the cam or hinge pin from bowing or bending at the center, which was previously a problem, and therefore reduces the risk of the cover separating from the phone housing, keeping the cover engaged with the phone.